 var websocket = null;
    let i;
    //判断当前浏览器是否支持WebSocket
    if ('WebSocket' in window) {
    /*ws://192.168.111.128:3000*/
    // websocket = new ReconnectingWebSocket('ws://49.234.154.170:3000');
    websocket = new ReconnectingWebSocket('ws://49.232.71.217:3000');
    // websocket = new ReconnectingWebSocket('ws://192.168.111.138:3000');
}

    else {
    alert('当前浏览器 Not support websocket')
}
    var jsonobj = { "name":"runoob", "alexa":10000, "site":null };
    //连接发生错误的回调方法
    websocket.onerror = function () {
    setMessageInnerHTML("WebSocket连接发生错误");
};

    //连接成功建立的回调方法
    websocket.onopen = function (e) {
    setMessageInnerHTML("WebSocket连接成功");
}

    //接收到消息的回调方法
    websocket.onmessage = function (event) {
        // var obj = JSON.parse('{ "name":"runoob", "alexa":10000, "site":"www.runoob.com" }');
        // setMessageInnerHTML(obj.name);
        // setMessageInnerHTML("sadsd");
    setMessageInnerHTML(event.data);
}

    //连接关闭的回调方法
    websocket.onclose = function (e) {
    console.log('websocket 断开: ' + e.code + ' ' + e.reason + ' ' + e.wasClean)
    console.log(e);
    setMessageInnerHTML("WebSocket连接关闭");
}

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
    closeWebSocket();
}

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        // let result = JSON.parse(innerHTML);
        // var source = { "name":"runoob", "alexa":10000, "site":null };
        // innerHTML = JSON.parse(source);
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
}

    //关闭WebSocket连接
    function closeWebSocket() {
    websocket.close();
}

    //发送消息
    function send() {
    var message = document.getElementById('text').value;
    websocket.send(message);
}